Covalent bond can be classified as single covalent bond, double covalent bond and triple covalent bond. In single covalent bond, two atoms share an electron pair or two electrons to make a bond. In double covalent bond, two electron pairs or four electrons are shared by two atoms. Similarly, three electrons pairs or six electrons are shared by two atoms in triple covalent bond. The atoms involved in the covalent bond have ability to attract the electron pair towards itself, this property is called electronegativity. The atom with greater electronegativity gets partial negative charge and the atom with less electronegativity gets partial positive charge.
